Just hours after news spread that Facebook engineer Jeff Verkoeyen had left the company amid frustration that Facebook still hadn’t released the Facebook iPad app he helped engineer came word from Mashable that Facebook will unveil it’s long-awaited iPad app at Apple’s upcoming media event on October 4th where the company will unveil the final shipping version of iOS 5 alongside, of course, it’s next-gen iPhone.

So why the long delay?

Well, Mashable cites anonymous sources familiar with the situation who claim that things were put on the backburner on account of the strained relationship between the two companies. You might remember that Apple originally wanted to integrate Facebook into Ping but ultimately chose not to, with Steve Jobs later explaining that Facebook demanded “onerous terms” Apple could not agree to. Further, there were rumors that Apple wanted to incorporate deep Facebook integration into iOS 5 but opted for Twitter instead due to similar disagreements over the deal.

The relationship between the two technology giants is warming up, however, thanks to the shared goal of beating Google — and the simple fact that Facebook and Apple may need each other. The former doesn’t have a mobile platform while Apple doesn’t have a social platform. The culmination of this renewed friendship: the launch of Facebook for iPad at Apple’s iPhone 5 media event.

At this event, our sources also expect Facebook to unveil a new version of Facebook for the iPhone, with design and speed improvements that mimic the iPad app.

The most interesting takeaway here, we think, is Apple forging a better relationship with Facebook as a result of both companies desire to stave off Google’s efforts with Android and Google Plus respectively. The last time Apple participated in an “enemy of my enemy is my friend” situation, it partnered heavily with Google to the detriment of Microsoft.

The dynamic and variables here here – i.e social media – are markedly different in this case but it’ll be interesting to see how the landscape takes shape should Facebook, in fact, align itself with Apple’s iPhone.